"Buzz" coming from the front disc brake area - help?

tlarwa · #1 12-17-2018, 07:46 AM

The front end of my fat tire bike (2014 Specialized Fatboy w/ carbon fork) "buzzes" when I ride. It has TRP hydraulic brakes and a 180mm front rotor. If I gently squeeze the front brake (just a touch) it goes away. When I tap on the rotor with my finger I can hear it contacting the brake (pads, I assume), but the rotor is centered and there is no rotor/pad contact when the bike is in the workstand. Anyone have any suggestions on how to eliminate the ride-induced buzzing noise? It doesn't affect the riding at all, but it drives me crazy.

Thanks!

oldpotatoe · #2 12-17-2018, 08:44 AM

Quote:

Originally Posted by tlarwa

The front end of my fat tire bike (2014 Specialized Fatboy w/ carbon fork) "buzzes" when I ride. It has TRP hydraulic brakes and a 180mm front rotor. If I gently squeeze the front brake (just a touch) it goes away. When I tap on the rotor with my finger I can hear it contacting the brake (pads, I assume), but the rotor is centered and there is no rotor/pad contact when the bike is in the workstand. Anyone have any suggestions on how to eliminate the ride-induced buzzing noise? It doesn't affect the riding at all, but it drives me crazy.

Thanks!

Is the rotor tight? Any side to side play when ya push on it? Tapping it with your finger shouldn't see it hit a brake pad.

Steve in SLO · #3 12-17-2018, 10:10 AM

Does the buzz change pitch as you change speed? If so, it is a rotational issue. If not, it is a harmonic issue.

Gummee · #4 12-17-2018, 11:49 AM

hose loose somewhere?

M

tlarwa · #5 12-17-2018, 06:27 PM

Just got the bike in the stand to take a look. When I spin the wheel there is no noise at all from the caliper area (no rubbing or anything). But when tapping on the rotor you can hear a metallic ringing sound. Imagine that vibrating through the front end while I'm riding! From what I can tell, it sounds like the spring clip between the pads is vibrating. I removed and reinstalled the pads, making sure the screw through the pad tabs and the prong clip is tight, and it is still the same. If I tap on the body of the caliper (where "Tektro Gemini" is printed) it makes the same ringing noise as if I was tapping on the rotor. So I'm pretty sure it's the pads and/or spring clip moving inside the caliper body. Any ideas how to mitigate this? It doesn't happen on the rear brake, and it's the same caliper, pads and clip. Arghhhhh

I tried to post a short video of me tapping so you can hear it, but the forum won't let me upload the video.

tlarwa · #6 12-17-2018, 06:38 PM

Okay, after thinking about it for a minute, I took the pads back out and spread the spring clip open quite a bit. Reinstalled them and I don't get the ringing anymore when I tap on it. Hopefully that was the issue, but I won't know until the next ride. I have a hunch that was it though. So simple ... I feel dumb that I didn't think of that right away!

Quote:

Originally Posted by tlarwa

Just got the bike in the stand to take a look. When I spin the wheel there is no noise at all from the caliper area (no rubbing or anything). But when tapping on the rotor you can hear a metallic ringing sound. Imagine that vibrating through the front end while I'm riding! From what I can tell, it sounds like the spring clip between the pads is vibrating. I removed and reinstalled the pads, making sure the screw through the pad tabs and the prong clip is tight, and it is still the same. If I tap on the body of the caliper (where "Tektro Gemini" is printed) it makes the same ringing noise as if I was tapping on the rotor. So I'm pretty sure it's the pads and/or spring clip moving inside the caliper body. Any ideas how to mitigate this? It doesn't happen on the rear brake, and it's the same caliper, pads and clip. Arghhhhh

I tried to post a short video of me tapping so you can hear it, but the forum won't let me upload the video.

oldpotatoe · #7 12-18-2018, 08:14 AM

Quote:

Originally Posted by tlarwa

Okay, after thinking about it for a minute, I took the pads back out and spread the spring clip open quite a bit. Reinstalled them and I don't get the ringing anymore when I tap on it. Hopefully that was the issue, but I won't know until the next ride. I have a hunch that was it though. So simple ... I feel dumb that I didn't think of that right away!

Don't be..noises are vexing..maybe I'll tell ya about I tore a bike down to parade rest, twice, looking for a 'noise', only to discover it was the zipper tab on my jacket bouncing..